Probably the earliest extant Gothic vaults in the Ile-de-France are those at Acy-en-Multien (Oise) and at Crouy-sur-Ourcq (Seine-et-Marne). Their outline is rectangular. Some intersecting ribs at Rhuis (Oise) are cited by M. Lefèvre-Pontalis as the oldest in the Soissonnais. Diagonals were put up, about 1115, at St. Vaast-de-Longmont (Oise), Orgeval (Seine-et-Oise), Viffort (Aisne), Airaines (Somme), and in other rural churches. The famous ambulatory vaults at Morienval were probably built about 1122. A year or two earlier, perhaps, are the side-aisle vaults of St. Étienne at Beauvais. Bury (Oise) shows the first extant half dome with ribs. Of the same time, about 1125, are the diagonals at Marolles, St. Vaast-les-Mello, Béthisy-St.-Pierre, Bonneuil-en-Valois, and Bellefontaine, all in the Oise department. Bellefontaine, whose date of 1125 is certain, has helped to place other churches of the transition by comparing their diagonals with its pointed intersecting ribs. Bruyères (Aisne) is about 1130, Poissy (Seine-et-Oise) and Villetertre (Oise) are about 1135, and so are the ribs of St. Martin-des-Champs at Paris. In the Aisne region are Berzy-le-Sec and Laffaux (c. 1140) and in the Oise region is Chelles, building at the hour when Suger undertook St. Denis (Seine), 1140 to 1144. Cambronne (Oise) and Foy-St.-Quentin (Somme) are about 1145. Such churches as Glennes (Aisne), St. Leu d'Esserent (Oise), and, close to the latter, Creuil's church of St. Évremont were building in 1150; so were Chars (Seine-et-Oise) and, near it, Pontoise,[23] whose ambulatory vaults some claim are prior to those of the procession path of St. Denis, and therefore a link between Morienval and Suger's abbatial. The big church at St. Germer (Oise) was begun about 1150, though certain of its features are more archaic than St. Denis, built before it. Some of these churches, called transitional, used wall ribs for their diagonals, others omitted them; in some the intersecting ribs were pointed, in others, semicircular. Mr. John Bilson, who contends that diagonals were used in Normandy some twenty-five years earlier than in the Ile-de-France, considers the early dates for these rural churches improbable, that scarcely any were anterior to St. Denis, that it was a case of little churches following the great churches, not vice versa. The earliest, he thinks, was St. Étienne at Beauvais (c. 1120), significantly close to Normandy. But Normandy did not suspect the value and fecundity of diagonals. That feat of creative genius none can deny to the Ile-de-France.